Unknown assailants chopped down approximately 30 olive trees and scrawled racist invectives in the West Bank village of Nahalin Saturday, in what Israeli authorities suspect is the latest in a string of attacks by radical Israeli settlers.

The words “Arab thieves” and “price tag” were found spray painted on rocks next to where 32 olive trees were uprooted, Ynet reported. Palestinians reported the incident to the IDF’s local coordination officer, who informed the Israel Police.

According to Israel Radio, police opened an investigation into the incident near the Etzion Bloc of settlements south of Jerusalem, which came amid a growing call for Israeli authorities to bring perpetrators to justice. Earlier on Saturday, former Mossad and Shin Bet chiefs criticized the Israeli government for not doing enough to prevent “price tag” attacks.

“Price tag” refers to acts of violence and vandalism by a small group of Jewish extremists to protest what they perceive as the Israeli government’s pro-Palestinian policies. Mosques, churches, dovish Israeli groups and even Israeli military bases have been targeted by nationalist vandals in recent years.

MK Issawi Freij (Meretz) on Saturday called “price tag” attacks a “racist cancer,” and said that the phenomenon was growing and in the end would harm the entirety of Israeli society. The left-wing politician said that Prime Minister Benjamin Netanyahu’s near complete silence over the issue, and the failure of the police and Shin Bet security services to curb the problem, are likely to increase fear and hatred.

This past week saw attacks in the northern towns of Fureidis and Yokne’am, with a mosque vandalized and dozens of car tires slashed. A Muslim extremist’s grave was also vandalized in a Haifa cemetery.

A US State Department terrorism report released Wednesday said Israel has not effectively countered and prosecuted radical settlers implicated in “price tag” attacks in 2013.

“Attacks by extremist Israeli settlers against Palestinian residents, property, and places of worship in the West Bank continued and were largely unprosecuted according to UN and NGO sources,” the report read.